Ockham's Razor does not say that the simplest explanation should be favored. It says that entities should not be multiplied beyond necessity (non sunt multiplicanda entia praeter necessitatem). In other words, new principles should not be invoked if existing principles already provide an explanation. If, however, the simpler explanation does not cover all the details, then additional "entities" are necessary.

Creationism is not an explanation. An explanation tells why something is one way instead of an alternative way. But creationism does not rule out any alternatives, since a creator God could have done anything. Because of this, creationism adds nothing to any argument. Thus, creationism is an unnecessary entity and, by Ockham's Razor, should be eliminated.